Shallow-water boat.



0. H. FOWLER.

SHALLOW WATER BOAT.

APPLICATION FILED JUNE 30, 1914.

1,1 32,923. Patented Mar. 23, 1915.

2 SHEETSSHEET 1.

IHE NORRIS PETERS C0,. PHOTC-LITHO. WASHING TON. Dv C.

C. H. FOWLER.

SHALLOW WATER BOAT.

APPLICATION FILED JUNE 30, 1914.

1,132,923. Patented Mar. 23, 1915.

2 SHEETSSHEET 2.

' ATTORNEYS v in the body of the boat.

CARL H. FOWLER, OF NEW YORK, N. Y.

' SHALLOW-WATER BOAT.

r Specification of Letters Patent. Patented Mar. 23, 1915.

Application filed June 30, 1914. Serial No. 848,126.

To all whom it may concern:

Be it known that LCARL H. FOWLER, a citizen of the United States, residing in the city, county, and State of New York, have invented a certain new and useful Improved Shallow-Tater Boat, of which the following is a specification.

My invention relates to boats, particularly those which are intended to navigate through shallow water. Tunnel boats are already known in which a propeller wheel is situated within a chamber or tunnel with In boats of this type, where no vacuum pump is provided to exhaust the air within the tunnel chamber, diliiculty is frequently experienced in securing a solid body of water in which the procally controlled, there is considerable loss peller can operate, this being sometimes due to the shape and location of the tunnel. Furthermore in boats of this class, where a vacuum pump has been provided, either directly connected with said propeller chamber or with a vacuum chamber superimposed thereover, having a vacuum pump connected with it, the shape of the tunnel chamber has been such as to materially lessen the general efficiency of the boat, and also difliculty has been experienced in preventing a rapid and wide fluctuation in the amount of water maintained in the propeller chamber. This fluctuation has been in part due to leakage and in part due to the continual entrance of bubbles of air and gases which come up through the bottom of the boat into the tunnel chamber, particularly when the boat is running or standing in shallow water. These air bubbles and gases rising to the top of the tunnel chamber enter the vacuum chamber, thus destroying the vacuum and thereby permitting the immediate dropping of the column or body of water which should be maintained over the propeller. This fluctuation in the height of the column of water over the propeller chamber or tunnel results in a corresponding fluctuation in the pressure or solid character of the water at the propeller in the propeller chamber. If therefore to overcome this condition the vacuum pump be operated continuously there is a considerable waste of power required for the pump. If the pump be operated only occasionally, unless automatieither in labor in looking after it or in the efficiency in the operation of the propeller.

A further defect in these tunnel boats has been in the amount of deadweight of Water which they have carried in their tunnels and in their superimposed. chambers wherever such are used. Now as the pressure of a column of water is determined by its height and not by its volume, it is possible to obtain the benefits of this increased pressurefound to be in the stern wave and wash created by the boat when in operation, this wave being such as to injure the banks of the canals or rivers in which they operate. This can be avoided by the construction herein described.

The objects of the invention are to improve the construction of tunnel boats and to increase their efliciency in operation.

A, further object of the invention is to provide and maintain at all times, both when starting and when under way, when going forward or when going backward, a solid body of water in which a propeller can efficiently operate.

A further object of the invention is to automatically maintain a solid body of water Within the propeller chamber at all times, both before the propeller is started and after it is in operation, the character of the water pressure within said chamber to be deter mined and automatically controlled by means of a superimposed standpipe and vacuum chamber.

A further object of the invention is to minimize the amount of dead weight of water carried in said standpipe and vacuum chamber by means of the construction thereof.

A further object of said invention is to prevent floating objects from entering the tunnel chamber that would otherwise obstruct the practical operation of said propeller.

A further object of said invention is to so shape and locate the after portion of said tunnel as to give the least friction to the water thrust backward from the propeller and at the same time to prevent the entrance of air within the rear of said tunnel which would thus destroy the effect of the vacuum maintained thereabove.

A further object of said invention is to so construct said rear end of the tunnel in relation to the stern of the boat as to prevent or neutralize the formation of stern waves or wash which always have a tendency to wash and injure the banks of the canal or river.

In order that my invention may be clearly understood reference is hereby made to the accompanying drawings forming part of this application and illustrating certain forms of construction by which myinvention may be carried out.

In the drawing Figure 1 represents a vertical longitudinal section through the boat equipped with my invention. Fig. 2 represents a bottom plan view of the boat. Fig. 3 represents a portion of the vertical longitudinal section shown in Fig. 1, upon an enlarged scale, showing a mechanical arrangement for the control of the vacuum pump, Fig. 4: represents, upon an enlarged scale and in part diagrammatically, a partial longitudinal section through the boat showing a modification in which an electrical arrangement is used for the control of the vacuum pump, Figs. 5 and 6 are horizontal sections taken on lines 5-5 of Fig. 3 and 66 of Fig. 4, respectively. Fig. "I repre sents a vertical section taken on line 7-7 of Fig. 1. Fig. 8 represents a rear elevation of the boat showing the relation of the stern orifice of the propeller chamber to the minimum water line. Fig. 9 represents a vertical section similar to Fig. 7, but of a modilied construction in which two propeller chambers or tunnels are used with a single vacuum chamber superimposed above one of the propeller chambers, Fig. 10 is a View similar to Fig. 9 of another modification in which the vacuum chamber is situated between the two propeller chambers and Fl 11 represents a rear elevation of a boat equipped with two propeller chambers as shown in Figs. 9 and 10.

Referring to the drawings, the boat may be of any suitable construction and as illustrated represents a light draft boat adapted to be propelled through canals or shallow water. The bottom of the boat 2, which in the construction illustrated is substantially flat, is provided, in the construction illustrated in Fig. 1, with a propeller chamber or tunnel 3 formed by raising the bottom of the boat with a forward wall 4- and a rear wall 5. The forward wall 4c slopes upwardly and rearwardly at a gradual angle so as to give easy access to the water approaching the propeller 6 which is mounted within the propeller chamber upon a propeller shaft 7 which extends through a suitable opening in the forward wall 4 of the chamber. Rear wall 5 of the chamber slopes, as to its top or roof portion, at a very gradual angle from the horizontal, to the point 8 at which the propeller chamber or tunnel is given a rear opening or orifice through the stern of the arched construction as shown in Fig. '1'. The

sides and forward end of the propeller chamber, which open on a level with the keel as shown in Fig. 7, are, of course, always submerged. The shape and position of the rear top wall 5 of chamber 3 and of the opening 8 therefrom are of great im portance in the general structure of the boat. The longitudinal cross-section of the top rear wall 5 of the chamber should be in practically a straight line and substantially parallel with the axis of parallel shaft 7. By this means, several objects are accomplished and advantages obtained. The propeller shaft is set at a slight angle to the horizontal. giving it a slight downward thrust, thereby washing the bottom of the canal or river and preventing the formation of the stern wave or wash so destructive to the banks of canal or river in the ordinary stern paddle boat or ordinary tunnel boat. By this construction also there is the minimum of friction and loss of power from the water passing through the tunnel or propeller chamber.

My invention contemplates the use of a vacuum. chamber connected with the propeller chamber, the air being exhausted from the vacuum chamber by a suitable pump so that water will be forced into the propeller and vacuum chambers because of the atmospheric pressure on the surrounding water, by which means the propeller will always be given a solid body of water in which to operate. The rear orifice 8 of the propeller chamber must be so positioned as to be entirely submerged in order to make efiectlve the apparatus of the vacuum chamber and pump referred to, for it is only bv havin a comaletelv air sealed )ro aeller opening at 8 of the tunnel be brought down to the keel line of the boat, there is found to be a marked loss of efficiency and increased friction because of the increased angularity of the rear wall of the tunnel. By arranging the rear wall of the tunnel and the propeller shaft substantially in the manner illustrated, a marked increase in efficiency is obtained over the constructions above referred to, the propeller shaft operating at an angle sufficiently slight to give a good thrust, and the parallelism of the shaft and rear wall of the tunnel reducing the friction of the water leaving the propeller as stated. Furthermore, the defect of the ordinary tunnel boat that it cannot back water or run backward efficiently is overcome by this form of construction.

Above the propeller chamber 3 and connected therewith at its highest point in the construction illustrated in Fig. 1, I superimpose a stand pipe 9 having integral therewith or connected thereto at its upper end a vacuum chamber 10 in which is provided means for controlling the height of the column of water in the vacuum chamber, and the operation of the vacuum pump. A pipe connection 11 extends from vacuum chamber 10 to a suitable vacuum pump 12, which may be of any suitable design and adapted to partially exhaust the vacuum chamber 10 when in operation.

Means are provided for automatically starting the vacuum pump in operation when the level of the water in the vacuum chamber drops below a predetermined point and for stopping the vacuum pump when the water in the vacuum chamber rises above this point. In the construction shown in Figs. 1, 3 and 5, a means is illustrated for conveniently accomplishing this purpose mechanically. A float 13 rests on the water in vacuum chamber 10 and is connectedby'a link 14 with a rod 15 mounted transversely in the walls of the vacuum chamber and extending out through one side of the same through a suitable air tight bearing in which rod 15 is mounted to oscillate. A crank 16 is secured to rod 15 on the outside of the vacuum chamber and has connected thereto a link 17 which moves longitudinally as the float 13 falls or rises and is so connected as to start or stop the vacuum pump under these conditions. A suitable means for accomplishing this result is illustrated in Fig. 1 in which the vacuum pump 12 is illustrated as having its shaft in alinement with the shaft of engine 18 which rotates the propeller shaft 7 of the boat. In this construction, connections are provided for coupling or uncoupling the vacuum pump to the engine in accordance with the movements of link 17. These connections may take the form of a bell-crank 18 connected to link 17, a link 19 connected to'bell-crank 18 and a bell-crank 20 connected to link 19 and adapted to operate a clutch to connect and disconnect the vacuum pump and the engine.

The float 13 and the connections described are so adjusted that when the float falls below a predetermined level, the Vacuum pump is set in operation, the air exhausted from the vacuum chamber, thus causing the water to rise through the operation of atmospheric pressure, filling propeller chamber 3, stand pipe 9 and the vacuum chamber 10 until the rising Water in vacuum chamber vl0 raises the float 13 above the predetermined level and stops the connection of the vacuum pump. When air or gases at any time enter through the bottom of the boat, coming into the propeller chamber and rising through the stand pipe 9 into the vacuum chamber 10, they cause the column of Water to fall in boats which are not equipped with the automatic regulating means described, as has been seen to be the case in boats in actual operation, and there is a rapid and wide fluctuation of the height of the Water in the stand pipe and vacuum chamber causing an uneven pressure and a less desirable character of. water for the propeller to operate on in the propeller chamber. Whenever the water in the propeller chamber falls so as to permit the propeller to operate partly in the v air and partly in the water, the propeller begins to race and rapidly loses efficiency.

The apparatus described overcomes this defeet and greatly increases the efficiency of the boat for operation in shallow waters.

I have illustrated in Figs. 4 and 6, a modified construction in which the operation of the float controls the operation of the vacuum pump by electrical means. In the construction illustrated, the pivot rod 15 is provided on the outer side of the vacuum chamber with an arm 16 carrying an electrical contact 21 which is brought into contact with a stationary terminal 22 secured to the wall of the vacuum chamber, when the float l3 falls and it is desired to start the vacuum pump into operation. An electrical circuit may be completed by this means and caused to start the pump into operation by any desired mechanism. In the construction illustrated, the movement of terminal 21 into contact with terminal 22 completes an electrical circuit 23 which includes a solenoid 24, which being energized causes a lever 25 to rock on its pivot and operate the clutch referred to to connect the vacuum pump with the engine 18, this move ment of lever 25 being opposed by a spring 26. It is obvious that my invention is not limited as to the feature of automatic regulation of the vacuum pump, to the particular constructions described which are merely illustrative.

I preferablyprovide a special form of construction of the stand pipe and vacuum chamber as illustrated. Since the hydrostatic pressure in the propeller chamber or tunnel is determined by the height of the column ofwater raised above it and not by the volumn of this column of water, I pro.- vide that the stand pipe 9 shall be of a com.- paratively small diameter, thereby materially reducing the amount of water to be.

carried as a dead weight by the boat. This stand pipe, as stated, at its upper end opens into a larger chamber, which I have'terrned the vacuum chamber 10, which chamber, because of its increased size, is not subject to the same rapid fluctuation in the height of the column of water that would be experienced if chamber 10 were of the same small diameter as the stand pipe 9, when a given quantit of air or gas is admitted into the stand pipe and vacuum chamber. Furthermore, the vacuum chamber 10 provides ample room in which to operate the float 1.3. I do not limit the apparatus described to any particular form or size for the combined height of the stand pipe and vacuum chamber may be anything-up to twenty eight feet, which is approximately the limit of atmospheric pressure at sea level. Experience has shown that for every foot that the water is raised in the stand pipe and vacuum chamber over the propeller chamber, the solidity of the water in the propeller chamber is increased to give the propeller water of substantially the same character that it would have if it were operating at the same number of feet below the outside water level, thus preventing the racing and slipping of the screw and increasing its efiiciency and value.

1 also preferably provide at the forward end and at the bottom of propeller chamber 3, and on a line with the keel, a series of straight deflecting rods 27, the purpose of which is to prevent floating sticks, roots or branches or other floating objects from entering the propeller chamber and becoming entangled with the propeller while in operation. These deflecting rods are placed only under the forward part of the tunnel or propeller chamber and are suitably supported to extend from the front end of the chamber to a line approximately beneath the propeller itself. Thus, the rods do not extend across the channel of the propeller or impede the water passing from the same. By this means the dilliculty often experienced in tunnel boats of having the propeller become impeded is overcome. I also preferably provide a man-hole 28 located in the forward part of the propeller chamber so that if anything does become entangled in the propeller at any time when the engine is reversed or otherwise, the man-hole may be opened and the obstruction removed.

Lalso, as a modification of the invention described, provide for the construction of two or more parallel propeller chambers or tunnels, in place of a single propeller cham ber d scribed, these propeller chambers be ing similar in their construction to the single chamber described. It often is of ad vantage to have a pair of propeller chambers, symmetrically disposed with respect to the longitudinal central line of the boat, in which propellers operate, so that, for example, one propeller may be reversed when the other is going forward. In this case, a single vacuum chamber 29 may be directly superimposed above one propeller chamber 8 as shown in Fig. 9, the vacuum chamber in this construction being connec ed with propeller chamber 3 by means of a vertical pipe 30, the vacuum chamber being connected to the other propeller chamber by means of an inclined pipe or channel 31. Or the vacuum chamber 29 may be mounted between and above the two propeller chambers 3 and 3 as shown in Fig. 10 and connected to the same by two inclined pipe connections 30 and 31. In either case, the vacuum chamber is provided with a pipe connection to a vacuum pump and preferably with a float or other device for regulating the height of the water in the vacuum chamber and the operation of the vacuum pump in the manner described. W hen two or more tunnels are thus used, their orifices in the stern of the boat as illustrated at 8 and 8 in Fig. 11 should be below the minimum water line but above the keel line as described in connection with the form of my invention in which but a single propeller chamber was used.

It is obvious that my invention is not limited to the specific means for performing the functions described but that equivalent means may be substituted therefor. My invention applied not only to the type of construction illustrated in the drawings but also to the construction illustrated in my application both filed June 30, 1914, entitled Improvement in propulsion of vessels Serial N 0. 848,127 and Improvement in boats Serial No. 84:8,128. In the first named of these the propeller chamber is formed by a hood fastened to the stern of the boat having a hull of ordinary construction, and in the second named co-pending application a structure intended for high speed propulsion is illustrated, in which the propeller chamber formed in the after part of the hull of the boat is of less height than that illustrated in my present application, so that the propeller is only partly inclosed by the propeller chamber extending in part below the same.

Having now particularly described my invention, what 1 claim and desire to protect by Letters Patent is as follows 1. A, boat havinga. propeller chamber open at the bottom and having a rear wall, the upper part of which slopes at a gradual angle from the horizontal downwardly and rearwardly to the stern of the boat, and extending through the stern with an orific below the minimum water line of the boat and above the keel line, a stand pipe superimposed above and connected with said propeller chamber, a vacuum pump, a float in the upper part of said stand pipe, and connections between said float and pump such that under certain conditions the pump is set in operation to exhaust the air from said stand pipe and propeller chamber and under certain other conditions the pump is rendered inoperative, substantiallyv as set forth.

2. A boat having a propeller chamber open at the bottom, a propeller shaft extending into said chamber and a propeller thereon, a stand pipe superimposed above and connected with said chamber, a chamber of larger lateral dimensions than said stand pipe into which said stand pipe opens at its upper end, a float in said enlarged chamber, a vacuum pump and connections between said float and pump such that said pump is set in operation whenever the water in said stand pipe and enlarged chamber falls below a predetermined height and is stopped when the level of the water reaches such predetermined height, substantially as set forth.

3. A boat having two propeller chambers open at the bottom and having rear orifices below the normal water line, a propeller in each of said chambers, a stand pipe positioned at a higher level than said propeller chambers, upwardly directed connections from the top of said chambers to said stand pipe, and means for exhausting air from said stand pipe, substantially as set forth.

4. A boat having two propeller chambers open at the bottom and having rear orifices below the normal water line, a propeller in each of said chambers, a stand pipe positioned at a higher level than said propeller chambers, upwardly directed connections from the top of said chambers to said stand pipe, means for exhausting air from said stand pipe, and a series of deflecting rods running longitudinally from the forward end of each propeller chamber to a line approximately beneath the propeller in each said chamber, substantially as set forth.

5. A boat having two propeller chambers open at the bottom and having rear orifices below the normal water line, a propeller in each of said chambers, a stand pipe positioned at a higher level than said propeller chambers, upwardly directed connections from the top of said chambers to said stand pipe, means for exhausting air from said stand pipe, a float in said vacuum chamber, a vacuum pump and connections between said float and pump such that said pump is i set in operation when the water in said stand pipe falls below a predetermined height and that said pump is rendered inoperative when the water in said stand pipe rises to'such predetermined height, substantially as set forth. 7

6. In a boat, the combination of a hull having a propeller chamber therein open at the bottom, said chamber having a rearwardly and downwardly sloping top wall, a propeller in said chamber, a shaft upon which said propeller is secured extending through the forward wall of said chamber, the axis of said shaft being substantially parallel to the rear top wall of said chamber, means for exhausting air from said chamber, and means for causing said exhausting means to operate only when the water in said chamber falls below a predetermined level, substantially as set forth.

7. In a boat, the combination of a hull having a propeller chamber rising above the normal water line of the boat and having an opening below the normal water line, means for exhausting the air from said chamber, and means for setting said exhausting means in operation and for rendering said exhausting means inoperative Whenever the water in said chamber rises to a predetermined level, substantially as set forth.

8. In a boat the combination of a hull having a propeller chamber thereon open at the bottom, a stand pipe superimposed thereover and connected therewith and having an enlarged vacuum chamber at its upper end, a float in said enlarged chamber, a vacuum pump, and connections between said float and pump whereby said pump is set in operation under certain conditions of water level in said chamber and is rendered inoperative under other conditions, substantially as set forth.

9. In a boat the combination with a hull having a propeller chamber thereinopen at the bottom and having a rear top wall sloping downwardly and rearwardly to an orifice in the stern of the boat, the top of which is below the minimum water line of the boat and above the keel line thereof, a shaft extending into said chamber, the axis of which shaft is substantially parallel with the rear top wall of said chamber, a propeller on said shaft wholly contained within said chamber, a vacuum chamber superimposed above and connected with said propeller chamber, a vacuum pump, and means controlled by the level of water in said vacuum chamber for controlling the operations of said pump, substantially as set forth.

10. In a boat, the combination of a hull having a plurality of longitudinally extending propeller chambers open at the bottom. and having downwardly sloping rear walls, shafts extending through the forward Walls agma fsaid chambersapproximately parallel to This specification signed and witnessed "s'aidl rear dwzllllls,bpropellers1 on said shafts this 27th day of Ju ie, 1914c.

Wit in sai c am ers, a sing c vacuum cham- 1 ber Within the boat communicating With the FOVLER upper portions of said propeller chambers, Witnesses:

and means for exhausting air from said DYER SMITH,

vacuum chamber, substantially as set forth. I. MCINTOSH.

Cqpies 91 this patent may be obtained for five cents each, by addressing the Commissioner of latents Washington, D. C. 

